Bring 2 cups of water and quinoa to a boil in a medium saucepan. Reduce heat to medium-low, cover, and simmer until quinoa is tender and water has been absorbed, about 10-15 minutes. Set aside to cool completely.

While the quinoa cools, prepare the vinaigrette. In a small bowl, whisk together olive oil, lime juice, red wine vinegar, minced garlic, cumin, salt, pepper, and oregano until well combined.

In a large mixing bowl, combine the cooled quinoa, black beans, diced tomatoes, cucumber, green onions, cilantro, and red bell pepper.

Pour the vinaigrette over the quinoa mixture and toss gently until all ingredients are evenly coated.

For best flavor, refrigerate for at least 30 minutes before serving to allow the flavors to meld.

If using avocado, fold it in gently just before serving to prevent browning.